From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4E90C3F2D1 for ; Thu, 5 Mar 2020 15:28:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 83ACD208CD for ; Thu, 5 Mar 2020 15:28:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726775AbgCEP2j (ORCPT ); Thu, 5 Mar 2020 10:28:39 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:56182 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726142AbgCEP2j (ORCPT ); Thu, 5 Mar 2020 10:28:39 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 10B6A296C1B Subject: Re: [PATCH v2 2/2] drm/bridge: anx7688: Add anx7688 bridge driver support To: Vasily Khoruzhick , Enric Balletbo Serra Cc: Icenowy Zheng , Jernej Skrabec , Nicolas Boichat , Laurent Pinchart , Neil Armstrong , David Airlie , Torsten Duwe , Jonas Karlman , linux-kernel , dri-devel , Andrzej Hajda , Maxime Ripard , Hsin-Yi Wang , Matthias Brugger , Thomas Gleixner , Collabora Kernel ML References: <20200213145416.890080-1-enric.balletbo@collabora.com> <20200213145416.890080-2-enric.balletbo@collabora.com> From: Enric Balletbo i Serra Message-ID: <5245a8e4-2320-46bd-04fd-f86ce6b17ce7@collabora.com> Date: Thu, 5 Mar 2020 16:28:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vasily, On 14/2/20 23:22, Vasily Khoruzhick wrote: > On Fri, Feb 14, 2020 at 2:20 PM Enric Balletbo Serra > wrote: >> >> Hi Vasily, >> >> Missatge de Vasily Khoruzhick del dia dv., 14 de >> febr. 2020 a les 23:17: >>> >>> On Fri, Feb 14, 2020 at 1:53 PM Enric Balletbo Serra >>> wrote: >>>> >>>> Hi Vasily, >>>> >>>> Missatge de Vasily Khoruzhick del dia dv., 14 de >>>> febr. 2020 a les 22:36: >>>>> >>>>> On Thu, Feb 13, 2020 at 6:54 AM Enric Balletbo i Serra >>>>> wrote: >>>>>> >>>>>> From: Nicolas Boichat >>>>>> >>>>>> ANX7688 is a HDMI to DP converter (as well as USB-C port controller), >>>>>> that has an internal microcontroller. >>>>>> >>>>>> The only reason a Linux kernel driver is necessary is to reject >>>>>> resolutions that require more bandwidth than what is available on >>>>>> the DP side. DP bandwidth and lane count are reported by the bridge >>>>>> via 2 registers on I2C. >>>>> >>>>> It is true only for your particular platform where usb-c part is >>>>> managed by firmware. Pinephone has the same anx7688 but linux will >>>>> need a driver that manages usb-c in addition to DP. >>>>> >>>>> I'd suggest making it MFD driver from the beginning, or at least make >>>>> proper bindings so we don't have to rework it and introduce binding >>>>> incompatibilities in future. >>>>> >>>> >>>> Do you have example code on how the ANX7866 is used in pinephone? >>>> There is a repo somewhere? >>> >>> I don't think it's implemented yet. I've CCed Icenowy in case if she >>> has anything. >>> >> >> It would be good to join the effort. Just because I am curious, there >> are public schematics for the pinephone that is using that bridge? > > Schematics is available here: > https://wiki.pine64.org/index.php/PinePhone_v1.1_-_Braveheart#Schematic > Would you mind to check which firmware version is running the anx7688 in PinePhone, I think should be easy to check with i2c-tools. Thanks in advance, Enric [snip]